The present invention relates to a use of complex cytokines in the maturation of dendritic cells, wherein the complex cytokines are produced by the stimulation of CD150, the expression of which is induced in EBV-infected B cells, and a method of preparing dendritic cells by using the use.
Dendritic cells are the strongest antigen presenting cells, and although they exist in small quantities in vivo, their controlling capability of T cell immunity are excellent. Also, when dendritic cells isolated from tissue or blood are stimulated by an antigen in vitro and then injected in vivo in the form of mature dendritic cells, the dendritic cells show immunogenicity. Accordingly, the dendritic cells are highly suitable for use as a cell vaccine for inducing immunity to specific antigens of tumor or pathogen (Inaba, K. et al., 3. Exp. Med., 178:479, 1993; Inaba, K. et al., Int. Rev. Immunol., 6:197, 1990; Hsu, F. et al., Nature Med., 2:52, 1996).
Techniques for obtaining and maturing dendritic cells are disclosed in many disclosures: mature dendritic cells are produced from immature dendritic cells derived from pluripotent cells that express either microphage characteristics or dendritic cell characteristics, wherein immature dendritic cells are brought in contact with a dendritic cell maturation factor comprising IFN-α (European Patent No. 922,758); Human CD34+ hemoblast is cultured with (i) GM-CSF, (ii) TNF-α and IL-3, or (iii) GM-CSF and TNF-α to induce the formation of CD1a+ hemoblast, and from the culture, CD1a+ human dendritic cells are harvested (European Patent No. 663,930); and peripheral blood cells are isolated and enriched in blood precursor cells that express CD34 antigen, and the cells are multiplied with hematopoietic growth factors associated with cytokines (WO 95/28479).
CD150 (also known as signaling lymphocyte activation molecule (SLAM)) is a type I trans-membrane glycoprotein belonging to the CD2/CD150 family of the immunoglobulin superfamily of proteins. In humans, CD150 is constitutively expressed on immature thymocytes and CD45RO+ memory T cells, and is considered as a molecule playing an important role in cell adhesion and signaling in the immune synapse between T cells and antigen-presenting cell (APC).
High levels of CD150 expression are frequently associated with B cell malignancies, and recently, many study results on effects of CD150 on intracellular signaling and the secretion of cytokines are being reported.
The inventors of the present invention found that CD150 expression increases on EBV-infected B cells, and based on the founding, they researched into how CD150 acts on EBV-infected B cells. As a result, the inventors confirmed that due to the stimulation of CD150, production of complex cytokines is derived in EBV-infected B cells, and such complex cytokines are used to rapidly produce mature dendritic cells from monocytes, thereby completing the present invention.